Motor-driven pump



1961 J. N. HALL ,997,957

MOTOR-DRIVEN PUMP Filed March 2, 1959 l 1 l lmllll HQ': 1 l I'll]:

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2,997,957 MOTOR-DRIVEN PUMP John N. Hall, Newark, Del., assignor toEnterprise Machine and Development Corporation, New Castle,

Del., a corporation of Delaware Filed Mar. 2, 1959, Ser. No. 796,302 12Claims. (Cl. 103-87) This invention relates to a motor-driven, submergedpump and more particularly, relates to an economical structure for sucha pump.

Various processing apparatus, for example, flushing or machine toolcooling systems incorporate means for pumping liquid through a conduitfrom a sump. These sump pumps are usually driven by electric motors; andthey need not be extremely efficient in their use of the power suppliedthereby because motors of practical size generally provide quite a bitmore power than is required for pumping the rather small quantities offluid required for flushing or cooling, for example. However, apparatusof this general type is sold in a highly competitive market, and it is,therefore, of great importance that the structure of the pump be assimple and economical as possible to permit the apparatus to becompetitively priced.

An object of this invention is to provide a structure for a motor-drivensubmerged pump, which is simple and economical to manufacture andassemble.

In accordance with this invention, a thin-walled mounting tube, forexample, made of commercially available tubular stock, extendsdownwardly from the motor into the sump. A hollow casing, for example,of inverted cupshape is inserted within the lower end of the tube andfastened therein against longitudinal movement. The motor shaft, or anextension thereof, for example, of sleeve form extends through a centralpassageway in the base of the cup into its interior, and an impellerblade is fastened to the end of this shaft extension. After the shaftand blade are inserted into the casing, the lower end is peripherallysealed by an annular plate which is secured to the lower end of thecasing, for example, by a spring reacting aaginst the lower end of themounting tube. This annular plate provides a central inlet opening intothe casing and confines pressures created in the outer periphery.

A discharge tube extends from a portion of the outer periphery of thecasing in line with the impeller blade for carrying liquid underpressure away from the pump. The casing or cup and discharge tube may bemolded in one piece of a plastic material; and they may, for example, beconnected to a substantially rigid discharge conduit by inserting itwithin the discharge tube and clamping the discharge about it to sealthe connection.

The discharge tube may be inserted through a slot in the end of themounting tube, and the cup may be longitudinally anchored within themounting tube by a resilient bar inserted within the end of the mountingtube which bears against one surface of the casing and forces it intocontact with a circular indentation formed in the wall of the mountingtube.

Novel features and advantages of the present invention will becomeapparent to one skilled in the art from a reading of the followingdescription in conjunction with the accompanying drawings in whichsimilar reference characters refer to similar parts and in which:

FIG. 1 is a view in elevation partially broken away in cross-section ofone embodiment of this invention;

FIG. 2. is a view in elevation of a portion of the embodiment shown inFIG. 1; and

FIGS. 3, 4 and are cross-sectional views respectively taken through FIG.1 along the lines 33, 4-4, and 5-5, and looking in the direction of thearrows.

In FIG. 1 is shown a motor-driven pump 10, for ex ample, incorporating afractional horespower electric motor 12 and a pump 14 submerged within atank of liquid 16. This arrangement is, for example, utilized in anapparatus for cleaning machine parts, such as gears and screws, ofgrease and foreign matter such as dirt or metal chips. Liquid 16 is, forexample, a solvent, such as kerosene. Motor 12 is mounted, for example,upon a horizontal plate 18 and a thin-walled tube 20 for con nectingpump 14 to motor 12 extends downwardly from motor 12 through plate 18, apredetermined depth into liquid 16. Tube 20 is fastened to motor 12, forexample, by spade bolt and nut assemblies 22.

Thin-walled tube 20 is, for example, made of a standardcommercially-available tubing stock, for example, two-inch O.D. brasstubing having a wall thickness of of an inch. A hollow casing 24, forexample, formed as an inverted cup is inserted within the lower end oftube 20 and restrained against vertical or longitudinal movementrelative to tube 20 by a circular indentation 26 formed in the wall oftube 20. The outside diameter of casing 24 is constructed and arrangedto fit snugly within the inside diameter of tubing stock 20. However,care is taken to insure that the diameter is not large enough tointerfere with insertion of casing 24 within the end of tube 20.

Casing 24, is for example, integrally formed in one piece together witha discharge tube 28. These parts are formed as a unit designated byreference character 30, for example, by molding them of a plasticmaterial, for example, a linear polyethylene. Use of a plastic materialnot only facilitates manufacture, but also aids in connecting the pumpto the discharge piping 32 as is later described in detail. Cup 24 alsoincludes a central passageway 34 in its base through which extendedmotor shaft 36 passes into the interior 39 of cup 24.

Extended shaft 36 includes, for example, a solid motor shaft 38 directlyconnected to motor 12 and a sleeve 40 which is slipped over shaft 38 andconveniently secured thereto, for example, by force fitting. Forcefitting provides a joint which is strong enough to transmit therelatively slight forces developed in pumping through the shaft.

An impeller blade 42 is secured to the end of sleeve 40 disposed withininterior 39 of casing 24, for example, by insertion within a slot (notshown), and a pin 44 extends through sleeve 40 and blade 42. Blade 42is, for example, a rectangular sheet of metal, for example, a sheet of4, inch thick half-hard brass to provide corrosion resistance. Sleeve 40is, for example, made of brass tubing stock to minimize corroslon.

An annular plate 46 is held in contact with the lower or open end of cup24 to confine pressures created in the peripheral portions of the cup byimpeller blade 42 to the vicinity of discharge tube 28. Hole 48 isprovided in the center of plate 46 for allowing a supply of inlet liquidto enter casing 24. A sheet 50 of screen material, for example, a discof brass 30 x 30 mesh screen formed of 0.013 diameter wire is held incontact with the lower surface of plate 46 which also may be made ofbrass for intercepting particles of foreign matter, such as metal chipsand filings to prevent them from entering casing 24.

Casing 24, annular plate 46 and screen 50 are, for example, held withinthe lower end of mounting tube 20 by a resilient bar 52, shown in detailin FIGS. 2 and 3, which for example, is connected to tube 20 byinsertion through holes 54 in its wall. Resilient bar 52 is, forexample, made of a serpentine piece of spring material, for example,inch stainless spring steel wire; and its extended area formed bycentral convolutions 56 presses against the lower surface of screen disc50 to maintain, in conjunction With circular indentation 26, the entirepump stantially rigid discharge conduit 32, for example, formed.

of conventional A inch O.D. copper tubing stock by having end 58 ofconduit 32 inserted within a recess 60 in the end of discharge tube 28.A clamp 62, for example, a resilient clamp similar in form to anautomobile radiator hose clamp is inserted over the end of dischargetube 28 and causes the inner surface of recess 60 to firmly embrace theouter surface of conduit 32. The plastic nature of the material formingcup 24 allows the force of clamp 62 to mold it to the outer surface ofconduit 32 and provide a pressure-tight seal about it.

The structure of motor pump is not only economical to manufacture asindicated by its utilization of major parts of standard stock materials,but it is also simple to assemble. After shaft 36 and impeller blade 42are assembled within interior 39 of casing 24, it is a simple matter tosecure casing 24, annular plate 46 and screen 50 in operative positionby simple insertion of spring bar 52 within holes in tube 20.

- An auxiliary inlet 64 is, for example, provided in the wall of tubeand the flow through it is filtered, for example, by a screen 66 of amaterial similar to screen 50. Inlet 64 is used, for example, when adouble suction to casing 24 through passageway 34, as well as throughbottom hole 48, is desired. This double suction may be advantageouswhere extremely dirty liquids are being pumped and the inlet screenstend to rapidly become blocked with solid matter or gum deposits.However, inlet 64 is not required since a sufficient supply of inletliquid is generally admitted through bottom hole 48.

I What is claimed is:

l. A motor-driven pump comprising a motor having an output shaft, athin-walled mounting tube having an inside diameter considerably largerthan the diameter of said shaft, one end of said mounting tube beingconnected to said motor and concentrically enclosing said shaft, ahollow casing inserted within the end of said mounting tube remote fromsaid motor, said casing being disposed within the walls of said tube,projection means connecting said casing to said mounting tube forrestraining longitudinal movement of said casing relative to said tube,the side of said casing adjacent said motor being cut out to provide apassageway through which said shaft extends into said casing, said shaftextending into said casing through said passageway, an impeller blademounted upon said shaft within said casing, said casing being cut outalong its axis to provide an inlet which allows fluid to enter saidcasing, and a discharge conduit connected to the outer periphery of saidcasing substantially in line with said impeller blade.

2. A pump as set forth in claim 1 wherein said hollow casing is shapedin the form of an inverted cup, said shaft extends through a relativelylarger hole in the base of said cup, and an annular plate is secured tothe open end of said cup to provide a central inlet and to confinepressures 4 created in its outer periphery to the vicinity of saiddischarge conduit.

3. A pump as set forth in claim 2 wherein said hollow casingincorporates a discharge tube extending laterally therefrom, a portionof the end of the mounting tube remote from said motor being cut out toprovide a slot, and said discharge tube extends through said slot whensaid hollow casing. is insertedwithin said mounting tube.

4. A pump as set forth in claim 2 wherein said hollow casing anddischarge tube are molded in one piece of a plastic material.

5. A pump as set forth in claim 1 wherein a circumferential indentationis formed in the wall of said mounting tube, and an upper surface ofsaid hollow casing bears against said indentation which helps restrainits longitudinal movement.

6. A pump as set forth in claim 5 wherein a resilient bar is engagedWithin the end of said mounting tube adjacent the end of said hollowcasing remote from said inentation, and said resilient bar bears againstthe end of said hollow casing for maintaining it in cooperation withsaid indentation locked against longitudinal movement relative to saidmounting tube.

7. A pump as set forth in claim 6 wherein an annular plate and a sheetof screen material are inserted between the end of said casing and saidresilient bar for respectively defining an inlet opening to said casingand preventing larger particles of foreign material from flowing throughit.

8. A pump as set forth in claim 7 wherein said output shaft comprises asolid shaft connected to said motor, and a sleeve is slipped over theend of said solid shaft and fastened thereto, and the end of said sleeveremote from said motor extends into said hollow casing.

9. A pump as set forth in claim 8 wherein said hollow sleeve is securedto said solid shaft by force fitting it thereto.

10. A pump as set forth in claim 8 wherein the end of said sleeveinserted within said casing is slotted, and an impeller blade isinserted within said slotted end and fastened thereto.

11. A pump as set forth in claim 10 wherein said impeller blade is arectangular sheet of substantially rigid material.

12. A pump as set forth in claim 1 wherein the side wall of saidmounting tube above said casing is cut out to provide a means forchanneling fluid through said passage way into said casing.

References Cited in the file of this patent UNITED STATES PATENTS1,801,103 Mummert Apr. 14, 1931 2,230,051 Conklin Jan. 28, 19412,468,704 Pippin Apr. 26, 1949 2,784,673 Namur Mar. 12, 1957 2,791,967Klauss May 14, 1957 2,872,084 Edwards Feb. 3, 1959

